We propose to investigate the influence of environmental factors on the physiological, biochemical and ultrastructural properties of the surface and extracellular polymers of cariogenic and non-cariogenic oral streptococci. We will study: 1) the quantitative chemical composition of cell walls of strains of Streptococcus mutans. For these studies walls will be dissolved enzymatically and the component polymers will be isolated and chemically and immunochemically characterized. 2) The synthesis and excretion of lipoteichoic acid, lipids, polysaccharides and proteins by cells in different conditions of growth and incubation. 3) The processes leading to resistance of cell wall antibiotic induced lysis and death (tolerance). It is anticipated that these investigations will provide a better understanding of the physiology and biochemistry of carcinogenic streptococci, of some of the factors that influence their ability to colonize, adhere, survive and at times, grow and metabolize in the oral cavity and of methods that may sensitize these bacteria to attack by antibacterial agents.